338 research outputs found
Efeito da aplicação de água salina do desenvolvimetno e comportamento fisiológico do coqueiro.
bitstream/CPATC-2009-09/20353/1/bp_27.pd
Impacto sofrido pelo coqueiro após o plantio definitivo: II. mudas com quatro e sete meses de enviveiramento.
bitstream/item/90669/1/CPATC-PESQ.-AND.-41-87.pd
Draft Genome Sequence of Erwinia toletana, a Bacterium Associated with Olive Knots Caused by Pseudomonas savastanoi pv. Savastanoi.
Erwinia toletana was first reported in 2004 as a bacterial species isolated from olive knots caused by the plant bacterium Pseudomonas savastanoi pv. savastanoi. Recent studies have shown that the presence of this bacterium in the olive knot environment increases the virulence of the disease, indicating possible interspecies interactions with P. savastanoi pv. savastanoi. Here, we report the first draft genome sequence of an E. toletana strain.D.P.D.S. was the beneficiary of an ICGEB fellowship. The laboratory of
V.V. was financed by Progetto AGER and ICGEB core funding
Draft Genome Sequence of Beneficial Rice Rhizosphere Isolate Pseudomonas aeruginosa PUPa3.
Published onlinePseudomonas aeruginosa PUPa3 is a rhizosphere-colonizing and plant growth-promoting strain isolated from the rhizosphere of rice. This strain has, however, been shown to be pathogenic in two nonmammalian infection models. Here we report the draft genome sequence of P. aeruginosa PUPa3.G.U. and M.K. were funded by the Ministry of Education, Science and
Technological Development, Republic of Serbia (grant no. 173019). G.U.
is also the beneficiary of FEMS Research Fellowship 2014-1. The laboratory
of V.V. was financed by ICGEB core funding
Quorum Sensing Influences Burkholderia thailandensis Biofilm Development and Matrix Production
Members of the genus Burkholderia are known to be adept at biofilm formation, which presumably assists in the survival of these organisms in the environment and the host. Biofilm formation has been linked to quorum sensing (QS) in several bacterial species. In this study, we characterized Burkholderia thailandensis biofilm development under flow conditions and sought to determine whether QS contributes to this process. B. thailandensis biofilm formation exhibited an unusual pattern: the cells formed small aggregates and then proceeded to produce mature biofilms characterized by “dome” structures filled with biofilm matrix material. We showed that this process was dependent on QS. B. thailandensis has three acyl-homoserine lactone (AHL) QS systems (QS-1, QS-2, and QS-3). An AHL-negative strain produced biofilms consisting of cell aggregates but lacking the matrix-filled dome structures. This phenotype was rescued via exogenous addition of the three AHL signals. Of the three B. thailandensis QS systems, we show that QS-1 is required for proper biofilm development, since a btaR1 mutant, which is defective in QS-1 regulation, forms biofilms without these dome structures. Furthermore, our data show that the wild-type biofilm biomass, as well as the material inside the domes, stains with a fucose-binding lectin. The btaR1 mutant biofilms, however, are negative for fucose staining. This suggests that the QS-1 system regulates the production of a fucose-containing exopolysaccharide in wild-type biofilms. Finally, we present data showing that QS ability during biofilm development produces a biofilm that is resistant to dispersion under stress conditions.
IMPORTANCE The saprophyte Burkholderia thailandensis is a close relative of the pathogenic bacterium Burkholderia pseudomallei, the causative agent of melioidosis, which is contracted from its environmental reservoir. Since most bacteria in the environment reside in biofilms, B. thailandensis is an ideal model organism for investigating questions in Burkholderia physiology. In this study, we characterized B. thailandensis biofilm development and sought to determine if quorum sensing (QS) contributes to this process. Our work shows that B. thailandensis produces biofilms with unusual dome structures under flow conditions. Our findings suggest that these dome structures are filled with a QS-regulated, fucose-containing exopolysaccharide that may be involved in the resilience of B. thailandensis biofilms against changes in the nutritional environment
Emissão de óxido nitroso em latossolo sob cultivos de eucalipto e vegetação de Cerrado.
Os sistemas florestais são responsáveis por parte das emissões de gases de efeito estufa (GEE). Dentre esses, destaca-se o óxido nitroso (N2O), que é um importante gás causador do efeito estufa. Devido sua capacidade de absorver energia, estabilidade na atmosfera e alta capacidade de reagir com a camada de ozônio. Nesse contexto, o objetivo desse estudo foi avaliar no início da época chuvosa, a emissão de N2O em plantios de eucalipto de diferentes idades e em mata nativa de cerrado, no Paranoá-DF. A emissão de N2O foi avaliada com câmaras estáticas no período de outubro a dezembro de 2013. O delineamento experimental foi o de blocos ao acaso, com três repetições. Os maiores fluxos de N2O foram observados nos dias (18/10/2013, 11/11/2013 e 22/11/2013), para o cerrado típico, eucalipto de quatro anos de idade e eucalipto de seis anos de idade, respectivamente, variando de 1,93 ug NN2O m-2 h-1 no eucalipto de seis anos de idade a 3,5 ug N-N2O m-2 h-1 no cerrado. Os baixos fluxos de N2O, que aconteceram no período avaliado parecem não ter se correlacionado com o EPSA
Guardiões e variedades locais de hortaliças em comunidades rurais do Semiárido brasileiro.
Suplemento. Edição dos Anais do 52 Congresso Brasileiro de Olericultura, Salvador, jul. 201
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